title: The use of immuno-double-diffusion tests in epidemiological studies of influenza in Spain.
abstract: The immuno-double-diffusion (IDD) test was used to detect antibodies against the prevalent influenza A (H3N2) viruses in sera collected weekly in Madrid from 1972 to 1975. A total of over 14 000 sera were tested. The proportion of sera positive in the IDD test was found to reflect the level of recent influenza A infection of the population.
mesh_terms: D000914:Antibodies, Viral / Q000032:analysis*; D006801:Humans; D005779:Immunodiffusion; D009980:Influenza A virus / Q000276:immunology; D007251:Influenza, Human / Q000097:blood* / Q000453:epidemiology; D013030:Spain
chemical_list: D000914:Antibodies, Viral